The invention relates generally to electronic packages, and, more particularly, to sealed electronic packages for use in rugged environmental conditions.
The proliferation of electronic devices in modern vehicles creates a number of manufacturing challenges in packaging the electronic devices to adequately protect electronic components and ensure reliable operation thereof. Especially for electronic packages which are mounted on the exterior of a vehicle, providing adequate protection for electronics can become a daunting task.
For example, electronic monitoring of brake wear for trucks, buses, and larger vehicles has become desirable to ensure proper performance of the vehicle and to comply with applicable regulations. By sensing an operating condition of the brakes for the vehicle or trailer, a warning signal may be provided to an operator of the vehicle, such as through a dashboard light or indicator, that one or more of the vehicle brakes should be serviced. Unacceptable or dangerous operating conditions may therefore be avoided, and inconvenient physical inspection of the brakes need not be as frequent.
To correctly monitor the condition of the brakes, the electronics and sensing mechanisms must be located underneath the vehicle near the brakes themselves, and are therefore exposed to varying temperature, pressure and moisture conditions, as well as exposed to a variety of engine fluids, lubricants, grease, brake fluids, debris, gravel, roadway composition coatings and by-products. Electronic components must therefore be carefully packaged to withstand such a harsh operating environment and reliably operate.
One known approach for protecting electronics from harsh environments is to contain the electronic components within a housing, and then fill or pack the housing with a silicon potting compound to insulate electronic components from adverse environmental conditions. The silicon potting compound, however, tends to result in bulky electronic packages. In one application for a brake wear monitor system, the housing of the electronic package must have a slim profile on the order of 0.5 inches or less. Achieving a profile such as this with silicon potting compounds is problematic. A suitable alternative to silicon potting compounds to protect electronic sensor packages is desirable.